A parcel depot forced to shut down with 15 staff members getting checked over by paramedics was brought to a standstill... by fabric conditioner.
The mystery substance put the Aylesford site into a lather after it was spotted oozing from a package.
As dozens of emergency workers rushed to the scene, the entire workforce - 50 people - had to leave the building for more than four hours.
The drama began at 5.30am last Friday with police sealing off the area around the Hermes factory on the Quarry Wood Industrial Estate. It was just before 10am when staff were allowed back in.
No-one needed hospital treatment.
Workers were prevented from going inside while fire crews and a Hazardous Area Response Team made the area safe.
A Hermes spokesman said: “There was an incident at our depot where an unknown substance leaked from a parcel."
He said: “The site was evacuated on the advice of the emergency services and thoroughly cleaned.
“Our teams worked hard to minimise the delays on the limited number of affected parcels.”
Later the company confirmed the alert was sparked by “two inert liquids, one of which was fabric conditioner, that had mixed from two separate leaking packages.”
At the height of the response five fire engines, an incident support unit, several ambulances and police were in attendance.
Tesco confirmed its distribution centre in Mills Road was also required to cancel some of its home food deliveries, due to the road closures.
The Hermes workers were forced to wait patiently outside the factory. One said: “We were just told we couldn’t go in by police and the fire service and there’s been a cordon since I got here. It must be something serious for all these engines, police and ambulance to turn up.”
The cordon was fully lifted around 10am and cars were able to drive through the estate again.
Cash handling depot Loomis was also temporarily caught in the cordon, which also affected Lake Road.